Piano tuning



(No Model.)

A. FELLDIN.

PIANO TUNING PIN.

Patented June 15, 1886 Witnesses J72 wzzior Z%j/Wm@; Mm 5% u PETERSPhmo-Lnhog w v Wzihhgmn. D. C.

UNITED STATES PATENT OFFICE.

ABRAHAM FELLDIN, OF ITHAGA, NE\V YORK.

PIANO TUNING-PIN.

ePEcLPIcATIoN forming part of Letters Patent No. 343,80 dated J 111181886- Application filed May 29, 1885. Serial No. 167,031. (No model.)

.To all whom it may concern:

Be it known that I, ABRAHAM FELLDIN, a citizen of the United States, anda resident of Ithaca, in the county of Tompkins and State Of New York,have invented a new and useful Improvement in String Stretching andTuning Devices, of which the following is a specification.

The object of my invention is to provide a simple, durable, andinexpensive device, applicable in general for the purpose of stretchingstrings and wires, keeping them taut, and adjusting the tension, butespecially adapted to replace the old tuning-pin fastening device instring instruments, particularly pianos.

The ordinary tuning-pins are more or less conical, and provided on theirsurface transversely with fine parallel thread-like grooves, to increasethe friction between them and the holes or sockets of the woodenframe,in which they are tightly fitted, to prevent them from turning andfrom getting loose by rising in their sockets.

By my present invention the tuning-pins need not be made conical, haveno tendency to rise from the sockets, may be inserted without applyingany force, and become loose to be readily lifted out of the sockets assoon as there is no longer any tension on the string.

The invention will be plainly understood by reference to theaccompanying drawings, in which Figure 1 represents a section of aportion of the iron frame of a piano having the tuning-pin securedaccording to my p resent invention, the frame being sectioned on thelinew w of Fig. 2. Fig. 2 is a plan view of a portion of the same. Fig. 3shows aslight modification of the tuning-pin, it being provided with agroove or rabbct wherein to coil the end of the string.

A is the iron frame, B is an agraffe, and O the tuning-pin.

In order to insure friction, as aforesaid, the

portion of the frame in which the tuning-pins are fastened hasheretofore been made of wood, as aforesaid. I make it of iron in onecasting with the rest of the frame. The portion of the frame in whichthe tuning-pins are inserted is about five-eighths of an inch thick. Ahole, 0,

to receive the pin,is bored cylindrical, not tapering, and the tuningpinO is also cylindri cal, to fit the hole 0, and is smooth upon itssurface, its upper end, I), being, however, square, as usual, to adaptit to be turned by the tuning-wrench. Concentric with and of largerdiameter than the hole 0 is bored, at its upper end, a flat-bottomedrecess, a, in the frame A, as shown in Fig. 1. A drill of the same sizeas the hole 0 is then run down at an inclination to the axis of the hole0 in such a manner that a portion is cut away at d from the rear wall atthe upper end of the hole 0, and also at d from the front wall of thelower end of the hole 0; or the rabbets may be made by a file or areamer, or in some other manner. By this construction the friction dueto the tension of the string D is not equally divided between thesurfaces of the tuning-pin andthe hole 0, but is condensed, so to say,at the points cf only, the tuning-pin acting asalever of the firstclass, with its fulcrum at c, the weight or resistance at f, and theforce acting at h 1n direction of the arrow, and being the tension ofthe string.

It is evident that the pull of the string must not be applied too nearthe fulcrum e, (which is the upper part of the front wall of the hole 0,or that nearest the agraffe,) for in that case it may not get sufficientleverage and insure sufficiently tight grip to prevent slipping. it isfor this purpose that I make the aforesaid recess a, which preventscontact between the pin 0 and the front wall of the hole 0, except at apoint determined by the depth of there cess a, and also prevents thecoil of the string D from going too near the fulcrum e. Agroove, 9, maybe made around the pin 0 by reducing its diameter at that point, as inFig. 3, for the purpose of retaining the coiled portion of the stringwithin the limits of the said groove, and in that case the recess a mayeven be dispensed with, though I prefer to use the recess with orwithout the groove 9.

It is evident that contact between the pins C and the frame A may beobtained at diagonally-opposite points, cf, at the extreme upper andlower edges of the hole 0 by simply drilling ahole of slightly-largerdiameter than the pin; but as that would induce wear by giving toolittle contactsurface, the construction shown in the drawings ispreferred.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. In a string stretching or tuning device,

IOO

the combination of the pin with a frame,-

A, provided with a hole or socket, 0, larger at d d than the said pin,to insure contact between the pin and frame at the points e f only 5 ofthe said hole when the string is stretched,

substantially as and for the purpose set forth.

2. In a string stretching or tuning device,

the combination of the cylindrical pin 0 with the frame A, having acorrespondingly-cylinio drical hole, a, enlarged at d d, in order toinsure contact at e f only while under the strain of the string-tension,substantially as and for the purpose set forth.

3. In a string stretching or tuning device,

the combination of the pin 0 with the frame A, having hole 0, to receivethe said pin, the said frame A, having a recess, a, at the upper end andconcentric with the said hole, and the said hole being enlarged at dd,to insure contact at e f only while under the strain of thestring-tension, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two witnesses, this 6th day of February,

ABRAHAM FELLDIN.

YVitnesses:

A. W; ALMQVIST,

CARL GULLBERG.

